kayu belian-Eusideroxylon zwageri -

The Standard Malaysian Name for the timber of Eusideroxylon zwageri (Lauraceae). Occasionally, the tree is known as tambulian in Sabah, while the European trade name for this timber is Borneo ironwood. The timber is monotypic. The sapwood is bright yellow when fresh, darkens on exposure and is sharply defined from the heartwood which is light brown to almost bright yellow when fresh and darkens on exposure to deep reddish brown, becoming very dark brown or almost black with age.